KVM: arm64: Restore PMU configuration on first run

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Restoring a guest with an active virtual PMU results in no perf
counters being instanciated on the host side. Not quite what
you'd expect from a restore.

In order to fix this, force a writeback of PMCR_EL0 on the first
run of a vcpu (using a new request so that it happens once the
vcpu has been loaded). This will in turn create all the host-side
counters that were missing.

Reported-by: Jinank Jain <jinankj@amazon.de>
Tested-by: Jinank Jain <jinankj@amazon.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/87wnrbylxv.wl-maz@kernel.org
Link: https://lore.kernel.org/r/b53dfcf9bbc4db7f96154b1cd5188d72b9766358.camel@amazon.de

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This commit is contained in:

Marc Zyngier 2021-06-03 16:50:02 +01:00

parent 2a71fabf6a

commit d0c94c4979

3 changed files with 8 additions and 0 deletions

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1

arch/arm64/include/asm/kvm_host.h

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4

arch/arm64/kvm/arm.c

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3

arch/arm64/kvm/pmu-emul.c

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